#include<iostream>
using namespace std;

void swap(int& a, int& b)
{
	int temp = a;
	a = b;
	b = temp;
}

int main()
{
	int a = 1;
	int b = 2;

	swap(a, b);
	cout << a << b << endl;

	system("pause");

	return 0;
}